core decrypt performance improvements

[tomholub]

can use native implementations for:

• rsa decrypt
• rsa verify
• s2k (maybe)

AES should not be needed as it's using native implementation on Node

[tomholub]

Current decrypt speed on my phone, rsa4096 (utf encrypted test)

D: <-- 200 OK https://localhost:47929/ (12250ms)
D: <-- 200 OK https://localhost:47929/ (10877ms)
D: <-- 200 OK https://localhost:47929/ (10874ms)

[tomholub]

Current Run all tests: seconds [33 30 30]

[tomholub]

Current rsa4096 utf encrypted test with just one key loaded: ms [6692 6080 5782]

[tomholub]

After doing rsa decryption in Kotlin:

• rsa4096 decrypt: ms [1375 532 477]
• Run all tests: seconds [13 10.5 10.4]

[tomholub]

After doing rsa verify modular exponentiation in Kotlin:

• rsa 4096 decrypt ms [956 503 360 399]
• Run all tests seconds [11.4 9.3 9.1]